With the latest news out of France, I would expect all EU countries to start looking at reforms, from EU and locally. Albeit the information is still scarce and responsibility still not clear, the view from all participating EU countries on local security and [possibly] immigration may take a foothold.
The EU has proven that it cannot provide security (financial or otherwise), with the state of the lower tier countries in financial turmoil, and the larger participants taking the brunt financially and with regards to security (let's assume for a second that the attacker / driver is not a local Frenchman), all participants will start asking, 'won't we be better off on our own? create our own market connections and enforce our own borders on our terms'. With the state of affairs worldwide, this is extremely likely.
It might be unsavory short term, but it might just make a lot of sense to leave the EU for the long term benefits. As Magixs says, with UK going out (and open to individual one on one trade agreements with all European countries), why would the others need the EU?
I noticed a lot of Germans say the UK stabbed them in the back... well realistically there is nothing stopping a UK-German citizenship open border agreement (or similar for every country on individual terms) as well as legislation on current employment and resident individuals from other countries.
So a lot of news still to come and a lot of market movers in the pipeline.
Successful trading and stay safe out there, the world seems to be getting crazier every day.
For every loss there should be at least an equal and opposite profit.